... ,x46,x52,x56,x60,x65,x70,L245,L2903) Standard: GB/T3091-2001, BS1387-1985, ASTM A53 ... .API 5L/API 5CT4) Use: Used for low pressure liquids delivery, such as water, gas, ... A21.4 American National Standard for Cement-Mortar Lining for Ductile-Iron Pipe and Fittings for Water ISO 21809 ... Petroleum and natural gas industries --External coatings for buried or submerged pipelines used in pipeline ...